front up vs let something slip

front up

verb
  • To admit or confess. 

  • To show up; to appear or present oneself. 

  • To lead or represent. 

  • To meet with one's best efforts. 

  • To face; to confront or challenge. 

  • To pay in advance or give with the expectation of being reimbursed later. 

let something slip

verb
  • To accidentally reveal a secret. 

How often have the words front up and let something slip occurred in a corpus of books? (source: Google Ngram Viewer )